Once Oregon opened up to settlement in the 1830s, Christian missionaries were sent to evangelize the territory. Marcus Whitman, a physician, and his wife, Narcissa, arrived in 1836 as missionaries to the Cayuse Indians and settled in the Willamette Valley.Tensions grew between the Whitmans and the Cayuse Indians and hit a boiling point during a measles outbreak in 1847. Cayuse chieftain Tiloukaikt suspected that the Whitmans were intentionally overlooking sick Indian children in favor of sick white children, for half of the Cayuse tribe died in the epidemic but almost all of the white children recovered.On November 29, the tribe burnt down the mission, and killed fourteen whites, including Marcus and Narcissa Whitman. Tiloukaikt and four other Indians voluntarily surrendered and were hanged for the Whitman massacre. Whitmans became popular symbols of Christian martyrdom. Stories often oversimplified the complex relations between the Whitmans and the Cayuse tribe.

In the 1830s the Hudson Bay Company--then the largest private landowner in North America -- opened the Oregon territory to settlement. The American Board of Commissioners for Foreign Missions sent a handful of missionaries to the territory, including the newly married Marcus and Narcissa Whitman in 1836. The Whitman's settled in the Willamette Valley and started a mission among the Cayuse Indians. Narcissa taught at the mission school while Marcus, a medical doctor, preached and practiced medicine. Their years in Oregon were full of frustration and tragedy. In 1839, their two-year-old daughter drowned and Narcissa began to go blind. Very few Cayuse expressed interest in converting. The Whitmans made little effort to contextualize Christianity to Cayuse life, instead encouraging the tribe to give up hunting and gathering for agriculture and teaching their children to speak and read English. Given the lack of results, the ABCFM closed the mission in 1842. Marcus returned East to raise new missionary support. When he returned to Oregon in 1843, he was one of the leaders of the "Great Migration," the first time a major wagon train made it all the way to Oregon by floating wagons down the Columbia River. As the influx of white settlers into Oregon swelled, the Whitman's new mission became a regular waypoint on the trail. This led to tension between the Whitmans and the Cayuse Indians who were convinced that the couple's first loyalties were to fellow whites rather than the tribe. The Whitmans adopted 11 children who had been orphaned on the trail and reopened their mission school with many Indian boarding students. The tensions between the Whitmans and the Cayuse reached the boiling point during a measles outbreak in 1847. White and Indian children alike fell sick, but while half of the Cayuse tribe died in the epidemic, almost all of the white children recovered. The Whitmans had tended to both groups, but given the variance in the mortality rate Cayuse chieftain Tiloukaikt suspected treachery. On November 29, the tribe burnt down the mission, killed 14 whites, including Marcus and Narcissa Whitman, and took several dozen others captive. The Oregon territorial authorities sent a militia to rescue the hostages and extract revenge. The "Cayuse War" ended with Tiloukaikt and four other Indians voluntarily surrendering themselves to be hastily tried and hanged for the Whitman massacre. The Whitmans' mission ended in their death and finished the Cayuse as an independent tribe; afterward the survivors were confined to a small reservation. The Whitmans had significantly greater influence in death than they had had in life. Like David Brainerd a century before, evangelicals placed the Whitmans on a pedestal to encourage others to engage in mission work. The Whitman's rough edges--like their unwillingness to acculturate to Indian life -- were smoothed over and their deaths were turned into straightforward examples of martyrdom for the faith, rather than cautionary tales about engaging with other cultures. Their sudden popularity left other, far more successful missionaries in the Oregon territory in relative obscurity, like Jason Lee, the first missionary to the territory, and Cushing Ellis, who founded Whitman Seminary (now, Whitman College) in 1859 as the first institution of higher education in Oregon.Oregon civic boosters joined the chorus in hopes of attracting attention, capital, and further settlement in the colony. By the end of the 19th century, such books as How Marcus Whitman Saved Oregon: A True Romance of Patriotic Heroism, Christian Devotion, and Final Martyrdom became best sellers for both Christian and trade presses. That title references an apocryphal legend attributed to Marcus Whitman. According to the tale, Whitman had met with U.S. President John Tyler when he returned to the East to raise missionary support. He warned Tyler about British intentions to retake Oregon and Tyler authorized him to lead the Great Migration to secure American control of the territory. There is no direct evidence of a meeting between the two men.